The ‘alien megastructure’ mystery around KIC 8462852 just deepened.
That F3 V/IV class star, hotter than the Sun and some 1480 light years from Earth – made headlines in September when an unusual dimming pattern was put down to a possible alien megastructure. But no radio signals could be detected from the system and, after a short time, a team under Tabitha Boyajian of Yale University proposed that the best fit was a comet cluster.
Just to avoid the tongue-twisting numbers of the star catalogue, it’s informally known as Tabby’s Star, after Boyajian.
The comet theory’s lately been put in question after Bradley Schaefer of Louisiana State University did a forensic search of old photographic plates dating back to the 1890s. Turns out the star has been dimming at least since then, and the dimming has been getting progressively more intense. Between 1890 and 1989 the star faded at least 20 percent.
That effect could be achieved by blocking the light with intervening objects. However, Schaefer has calculated that you’d need too many comets – 648,000 of them, each 200 km across. And the pace at which the dimming cycles have intensified also seems to rule out an alien megastructure – it seems to have been built far too quickly.
Remember, we’re talking about engineering on Jupiter scale – and sure, you could suppose that it was built with self-replicating nano-bots, but the logic is circular (to prove it’s an alien megastructure built with nano-bots, you first have to assume that it’s an alien megastructure).
My take? I’m still leery about aliens. Sure, it’s always possible, but the ‘megastructure’ idea is one we thought up – humans, a species with particular behaviour patterns and a long history of exploiting environments the edge and beyond. The thinking goes that as a civilisation expands, its energy needs go up – along with living space – prompting the need for space-based collectors to grab more energy from the local sun.
That’s true of our civilisation, sure. However, who says that aliens would do the same and need the megastructures? They’re alien, remember. For all we know, there might well be intelligent life on one of the planets around the star, and they’re quite happily sitting there living the lives that placid yellow blobs live, and don’t want to go anywhere or build anything, thank you very much.
I covered the ‘alien blob’ idea off in my sci-fi novella ‘Missionary’, which you can get on Amazon.
If there are aliens? Great, and we certainly mustn’t rule out the possibility. But I’m not holding my breath.The actual answer just now is ‘nobody knows’. However, KIC 8462852 is going to get some close attention in the next little while. Odds are on that what we’re seeing is natural, but I figure we’re probably going to discover something – something surprising, likely serendipitous – and we’ll learn from it.
Whatever we find, I know it will be cool.
Copyright © Matthew Wright 2016